Pre-Administration of Saccharomyces boulardii-Derived Postbiotics Effectively Prevents Dextran Sulfate Sodium-Induced Colitis in Mice

Ulcerative colitis (UC) is effectively alleviated by <i>Saccharomyces boulardii</i> (<i>S. boulardii</i>), an important probiotic. Postbiotics, defined as beneficial non-viable microorganisms and/or their components, can potentially improve gut health. In this study, we utilized <i>S. boulardii</i> to prepare postbiotics via freeze-drying and spray-drying methods, characterized the resulting postbiotics, and investigated their efficacy and underlying mechanisms in preventing UC. In a mouse model of UC induced by dextran sulfate sodium (DSS), we found that prevention with two forms of <i>S. boulardii</i> postbiotics alleviated colitis symptoms triggered by DSS, mitigated colon tissue damage, maintained the distribution of intestinal occludin and ZO-1 proteins, and suppressed the secretion and expression of TNF-α, IL-1β, and IL-6 in serum and colon tissues. Additionally, <i>S. boulardii</i> postbiotics mitigated dysbiosis by modulating gut microbiota composition, including the balance between Bacteroidota and Firmicutes (F/B), as well as the levels of <i>Akkermansia</i>, <i>Muribaculaceae</i>, <i>Dubosiella</i>, and <i>Turicibacter</i>. In conclusion, as a novel biotherapeutic agent, <i>S. boulardii</i> postbiotics effectively prevent DSS-induced UC in mice. Compared to live <i>S. boulardii</i>, postbiotics may hold greater potential for UC prevention.